python: fix SDK logic to yield or not yield messages

[reyammer]

Context:

sec-gemini/sec-gemini-python/sec_gemini/session.py

Lines 617 to 631 in 97939a8

	if msg.status_code != ResponseStatus.OK:
	log.error(
	"[Session][Stream][Response] %d:%s",
	msg.status_code,
	msg.status_message,
	)
	break
	# Check if this message is about a tool call; if so,
	# deal with it and reply to the backend without
	# yielding the message -- it's not for the user!
	if msg.message_type == MessageType.LOCAL_TOOL_CALL:
	log.info(f"Received tool call request: {msg.get_content()!r}")
	tool_output_message = self._execute_tool(msg)
	await ws.send(tool_output_message.model_dump_json())

Currently it seems that:

• we do not yield error messages (which is not ideal as we are hiding important error information)
• we yield local_tool-related messages (the idea was that we would not yield them, that seems an implementation bug)